JavaFX Java GUI Tutorial - 5 - Creating Alert Boxes Video Lecture | JavaFX Java GUI: Learn to build Powerful Applications - Front-End Programming

alright guys in this video what I want
to do is I want to show you how to
create in our work box in other words
you guys make all them pop-up windows
but what this does is it's going to show
you guys how to add multiple windows in
the same program so remember in the last
video I showed you guys how to create
multiple scenes but all that did is it
just change the view inside your window
change the content however if you ever
want to have multiple windows like this
for example if I go to file settings in
this you see that we now have two
completely separate windows that we can
interact with if you ever want that
functionality then well pay attention
because I'm going to show you now I
already saved us some time by keeping
some of the stuff from my last video
I'll show you guys what we are working
with right now so again I just made a
really simple plain scene and my button
doesn't even have any functionality
right now so again this is my starting
point nothing new nothing I needed to
type over now for reason
always a good idea to pretty much build
these in new classes so if you
right-click your source you can just
choose new Java class and I'm just going
to name mine like alert box and I
actually already have all the stuff I
need copied so copy that down or you can
just got my github page and copy it
whatever but anyways we want to make one
single method in here and that method is
going to be called display so it's going
to be public I'll just make it static so
we don't have to create any objects so
static void display now again what I can
do is I can just set a string to say
okay here at the new window and give a
title but since whenever I'm teaching
these tutorials I don't only just want
to teach you guys but I want to build
these little classes so if you ever need
an alert box for your program you can
actually just arm you know go to my
github page copy it and throw it in your
program so what I'm actually going to be
doing is this I'm going to be passing in
two parameters one
is going to be the title in the other
one is just going to be a simple message
that you display to the user so that way
it's customizable for pretty much any
program now the first thing that you
guys need to do is this since we're
pretty much making an entirely new
window we're going to need to make a new
stage object then just like before I'm
going to name it window again and since
these are in different classes we can
name both of them window shouldn't
interfere with each other so window and
just set this equal to new stage so
right now we just have a blank window
that's it now should hold on I need a go
P I'm going to pause my video and I am
back by the way I'm getting myself some
more space I got these um like caffeine
pills off of Amazon I hate coffee and I
really don't like soda but I was working
on a rest client or just a little
program for my website and they make me
pee like all the time so if you guys are
thinking about getting caffeine caffeine
pills um yeah just heads up that's what
they do so okay I don't need a comment
where was I all right created a window
so what this alert box is going to do
again whenever they click the button
from the first scene it's going to
display this you know just by Kay you
open up a new window and then click OK
hover
alert boxes they typically behave in a
certain way for example let me show you
this you see whenever I open up this
window just in my IntelliJ you see
whenever I click this try to click the
background it's saying you can't do that
you need to take care of the window that
you just opened first and that's what a
lot of alert packs alert boxes and new
windows do so I'm going to show you guys
how to add that functionality so for the
window which is the main window you can
call in it modality and in here there's
actually parameter right there
application model or modal however you
save now what this does in all
is saying is that we are going to block
input events or user interaction with
other windows until this one is taken
care of
so again just like I showed you guys
with the settings window that's what's
going to happen now of course we still
need to set it up like before so we can
set the title and the title that appears
on here we're just going to set to
whatever title you passed in whenever
you wanted to display this and for the
window we can just set we'll give it a
minimum width of like 250 pixels all
right so now our basic window is set up
of course let's go ahead and add
something to it so label label equals
new label and of course that's just um a
little bit of text what text do you want
to appear well you can just set that
text to whatever message you passed in
so again you're going to pass it in the
title and a message the title is going
to be the title of the window and the
message is just what the mono like
whatever message you want to send to the
user now for the button it's going to
have one button on here called the close
button and all we need to do to set this
up is add some text to it and I'll say
close the window now of course the
functionality for this is close button
set on action II window dot close simple
enough now of course just like before we
always need allow even though that this
is a really simple little pop-up window
I'll set equal to new VBox just because
I think it sounds funny into the V box
that could be a nickname for something
but I don't know well but it sounds like
it would be a prefer to nickname for
something VBox I'm going to put these
right in this v bucks oh man I am
definitely immature all right so
children at all we have the label that
we on it want to add in we have a close
button that we
add and one other thing that actually
wanted to do is this you can actually
set the alignment for your entire layout
and if you call position center is just
going to Center everything so it's nice
like Center aligned simple enough
now of course just like any other window
it needs a scene this is the last thing
we have to do create a new scene so new
scene thought it would fill out for me
by the way I love this is going to sound
a like I'm the laziest person ever but I
love JetBrains IDs IntelliJ it you like
start typing one thing and it knows
exactly what you're going to type so
sometime I'll just like start typing um
like this like I type WI window and then
I'll type like one character and I'll
just like wait for it to uh like
sometimes I'm just waiting there like oh
it's going to write the code for me but
uh you know have to start doing some
stuff it's making me incredibly lazy but
my god these IDs are amazing anyways
what are we talking about
alright so we're making a new scene we
added the scene to the window nothing
new and the last thing we need to do is
we need to show now check this out
so before in our programs we just showed
which pretty much means display it to
the user
however instead of just our regular show
I'm going to call this method show go up
and wait now actually if I hover over
this and hold ctrl Q let me see if it
gives all right so it says show this
stage and wait for it to be hidden or
closed before returning to the caller so
essentially what this is going to do is
it's going to display this window and
before you go back to here before it
returns it needs to be closed so you see
this a lot in conjunction with this
essentially what this is going to do is
it's going to block any user interaction
and until this alert box is closed
pretty awesome so the last one thing
that we need to do is this where are you
all right for the button remember let me
run this right now and show you guys
what's going on so for the button it
says click me and nothing happens and
that is because we need to add the
functionality so button dot sets on
action now whenever you click it we just
want to say alert box which is that
class that we just created and that
method was called display now remember
whenever we call this we need to pass in
a title and a message so the title I'll
just write um title of the window or a
title of window just so you guys can see
exactly what's happening and for the
message to display I'll say wow this
alert box is awesome all right looking
good now hopefully when you run this we
click me and check this out
it creates a new window but it doesn't
get rid of the old window but look what
happens whenever I try to interact with
it I don't know if you guys well you
guys can't hear that but it there's a
little ding saying uh-huh you can't
click it I can't see I'm trying to close
this right now
it says on you open me you take care of
me first so we can just either close it
like this or the button closes it as
well but anyways once that's closed we
can interact with this click it again if
we want close it out boom row suit so
again this isn't just for displaying
little pop-up messages you can actually
use the same technique whenever you want
to create entirely new complex windows
like this however there are some nuances
that and I'm going to be showing you
guys that in the next couple videos but
for now thank you guys for watching and
we'll see you next time